Linkage map construction and detection of QTLs associated with earliness, fiber quality and yield in an interspecific cross between Gossypium hirsutum L. and Gossypium barbadense L.

Genomics–based approaches offer unprecedented opportunities for crop improvement. Mapping of the chromosomal regions affecting qualitative and/or quantitative traits using molecular markers is receiving a growing attention in the last few decades. We used 50 EST, 18 EST-SSR, 36 SSR primers and 64 AFLP primer combinations to develop a molecular linkage map of cotton employing F2 segregating population obtained through an interspecific cross between Giza 45 (G. barbadense) and Tamcot Luxor (G. hirsutum). Analysis of segregation among the resulting 60 F2 individuals was performed using 1 EST, 4 EST-SSR, 14 SSR primers and 10 AFLP primer combinations that revealed consistent polymorphic patterns and were employed for constructing a genetic linkage map that included 210 molecular markers located on 26 linkage groups and spanning a total length of 3503.8 cM. We detected 81 significant QTLs related to earliness, high yield, and fiber quality, which is promising for a better understanding of the cotton crop. Our map is covering ~75.2% of the total recombinational length of the cotton genome with an average marker interval of 16.7cM. SSR markers were used to assign the linkage groups to specific chromosomes. Seven linkage groups were assigned to chromosomes. This map represents the first map for the intercross between Giza 45 and Tamcot Luxor and could be considered as a framework map to overcome the limitations of conventional breeding for the improvement of cotton yield, earliness and fiber quality related traits.